Appratus for cleaning metal articles.



J. D. PHILLIPS & C. HAMBUEGHEN. APPARATUS FOR CLEANING METAL ARTICLES.

APPLICATION FILED JUNE 22, 1911.

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J. D. PHILLIPS & O. HAMBUEGHEN.- APPARATUS FOR CLEANING METAL ARTICLES.

APPLICATION FILED JUNE 22, 1911. 1,035,633. Patented Aug. 13,1912.

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UNITED STATES PATENT OFFICE.

JAMES J). PHILLIPS AND CARL HAMIBUECHEN, OF MADISON, WISCONSIN, ASSIGNORS TO RAMSAY-VANCE SALES COMPANY, A CORPORATION OF WISCONSIN.

APPARATUS FOR CLEANING METAL ARTICLES.

Patented Aug. 13, 1912.

Serial No. seam.

.faces of silver, gold, copper or other metals,

to remove all tarnish and other foreign matter therefrom, and to cleanse and purify in such manner that the surfaces will become chemically clean and sanitary. The cleaning is effected by electrolytic action, and the subsequent cleansing and sterilizing are so conducted that the silver or other metal is not injured either by the cleaning electrolyte or by any other of the agencies used.

Various electrochemical methods for cleaning silver have heretofore been proposed, wherein the articles to be cleaned are immersed in a hot alkaline solution held in a tin lined vessel or in an aluminum dish or 46 silver.

' electrical connection ma basket (see British Patent No. 7027 of 1905 to Ransford). With such an arrangement, the silver becomes the cathode of a voltaic couple, and the coating or tarnish is electrolytically reduced. But in practice, these methods are notsatisfactory. The tin or aluminum becomes coated with a film or covering which prevents efi'ective electrical contact with the article to be cleaned, therearticle to. be cleaned, for the entire time during which said articles are wet by theelectrolyte, and the electrolytic action there by maintamed not only reduces the coating of tarnish on the articles but subsequently covers the cleaned surfaces with a thin coatmg of hydrogen which effectively shields the surfaces from any possible injurious attack of the electrolyt V For a full understanding of the invention, reference may be had to the following detailed description, taken in connection with the accompanying drawings.

In the drawin s Figure 1 is a side elevatlon of the comp ete apparatus with certain portions broken away; Fig. 2 is an end elevation of the same; Fig. 3 is a detail of the container wherein the cleaning operation 1s etfected. Fig. 4 is a plan of the same and Fig. 5 is a perspective view of the grid whereb effective eleotrical connection is maintalned at all times between the container and the articles to be. cleaned.

The apparatus shown in the drawing comrises a stand having a plurality of cast iron legs 1 which carry a plurality of fiat platforms 2. On these plat/forms rectangular receptacles 3 and 4 are mounted. Receptacle 3 may be made of tinned metal, of granite ware or of earthenware, and is used to hold .the electrolyte or cleaning fiuid. Receptacle 4 may be of similar material and contains clean water for washing or rinsing the silver after the tarnish has been removed therefrom. These receptacles are provided respectively with steam inlets 5 and 6 whereby they may be heated to any desired temperature and whereby their liquid contents may be continuously stirred or agitated. Supported above this stand and its receptacles 1s a table having four legs 7, each of which is formed of angle iron and each of which embraces a corner or leg of the stand and is adapted to slide up and down thereon. The top part of the table comprises a track or guideway 8 equipped with rollers 9 below which a perforated container 10 is swung in stirrups 11 and 12. This container is used to hold the silverware or other articles to be cleaned while they are. undergoing ,the container is made.

it may be made of aluminum or other metalv strongly electropositive. The bottom of the receptacle is fiat and the bottom and the sides are perforated. Vithin the container and raised or projecting above the flat bottom is a id or framework 18 adapted to serve as t e auxiliary metal in establishing efiective electrical connection between the container and the articles to be cleaned during the time when the, articles are exposed to the action of electrolyte. This r1d preferably consists of a plurality 0 straight wires 19 which carry another set of wires 20 crosswise thereon and electrically welded thereto.

The entire structure has good electrical conductivity in every direction and may be regarded as integral throughout. The grid is heavily tinnedso that it will present to the electrolyte a surface which is electronegative to the zinc or other metal of which Other metals than tin may be used for this surface, but preferably it should be a metal like tin which is intermediate in solution tension between the cleaning metal and the metal to be cleaned. The entire grid is permanently soldered to the bottom of the container as at the corners 21.

The method whereby this apparatus is used is as follows: An alkaline solution is placed in receptacle 3 to serve as the electrolyte or cleaning fluid. A suitable solution may be made by dissolving one tablespoonful of baking soda (sodium bicarbonate) and one-half tablespoonful of common salt in every quart of water used. To secure quick dissolving of the salt in the water, the container 10 maybe raised and lowered to serve as a mixer. Simultaneously heat may be applied at the steam jet 5. During this mixing operation the tinned wire grid is effectively cleaned through the galvanic action set up by the short circuited couple of which the zinc is anode and the-grid is cathode. As soon as the grid is cleaned it becomes enveloped in a layer of hydrogen which so polarizes the couple as to prevent the further flow of current. The

container 10 is lifted from the electrolyte and filled with articles to be cleaned such as table silver or the like. These articles rest directly on the cleaned grid 18 and are therefore in good electrical connection with the zinc container. lowered into the heated alkaline electrolyte and allowed to remain there until the electrolytic action has completely cleaned the tarnished surfaces. Tarnish is ordinarily a sulfid or an oxid of the silver and acts like The container is then whereof the zinc is anode and the silver articles are cathode. Current flows from the zinc to the-silver through the electrolyte thereb liberating hydrogen which combines with the oxid or the sulfid to form water or hydrogen-sulfid. This reaction continues until all the oxid or sulfid is reduced to metallic silver; thereafter the silver surfaces become coated with a thin layer of hydrogen bubbles and the current cases to flow. At the zinc electrode, a film or covering forms on the metal but this is so porous that it does not stop the electrolytic action and since the tinned grid is so arranged as to maintain at all times a' good electrical connection between the zinc and the silver, the cleaning operation is in no way interfered with.- Thus far in the cleaning operation, no silver has been removed from the surface and there has been, as described, merely anstill remains the problem of getting the articles out of the electrolyte and freed from all corrosive agencies before any retarnishing or recombining can take place. It happens that hydrogen sulfid, such as is produced by the reaction above described, is somewhat soluble in the sodium bicarbonate solution and may there be' detected after the electrolyte has been in normal operation for atime. Also the bicarbonate solution when highly heated, as b a steam jet, has a tendency to liberate O and to break down into normal sodium carbonate, forming a solution which is a very good solvent for the hydrogen sulfid. It is consequently inevitable that when the apparatus herein described is used in ordinary kitchens andv pantries, the electrolyte, after a certain use,.

will reach a condition chemically active with respect to silver and capable of tarnishing by mere contact. It is for this reason that the further steps of the method herein described must be carefully followed.

After the tarnish has been removed by immersion in the electrolyte as above described, the sulfid-charged electrolyte must be removedfrom the clean and sensitive surface with such rapidity and under such conditions that the silver is given no opportunity for retarnishing. A washing or rinsing operation, if suitabl conducted, will effect this result. One e ective method of cleansing consists in lifting the container out of the electrolyte; while it still holds the cleaned articles, and immediately plunging the container and its load into the receptacle 4 of heated wash water. Under the agitating action of the steam jet 6, this water washes off the last traces of the electrolyte and leaves the silver chemy. clean,

and sterile. During this entire operation of lifting the silverware out of the electrolyte and, rinsing it off with hot water, the articles to be cleaned are retained in good electrical connection with the electropositive metal and the electrolytic action is thereby kept up and the silver enveloped in its layer of protective hydrogen for the entire time during which it is wet by the electrolyte. No retarnishing can take place, and the silver is left finally in a clean and sterile condition.

We claim:

1. Apparatus for cleaning tarnished metal articles comprising aperforate container which is electropositive to the articles to be cleaned, and a support for such articls within said container, said support comprising wires welded together to form a structure which is inte ral throughout, said structure having a sold er'ed connection with said container, and also have a contact surface which is electronegative to the metal of said container.

2, Apparatus for metal articles comprisi'n a perforate zinc container havin a gri soldered thereto, said grid being integral throughout, and comprising wires welded together and having a tinned surface exposed for contact with the articles to be cleaned.

3. Apparatus for electrically cleaning tarnished metal articles comprising a perforate container composed of zinc, and having a flatbottom, said container being provided with a projecting wire grid soldered to said fiat bottom and presenting a tinned surface to the electrolyte, said wire grid being integral throughout, and having its wires welded together and ada ted to maintain good electrical connection etween the articles to be cleanectland the container, so long as said articles are exposed to the action of the electrolyte.

4. In an appa atus for cleaning metal articles, the combi ation of. a receptacle for cleaning tarnished holding an alkalin electrolyte, means for heating said electro yte, a second receptacle for holding water, a perforate zinc container for olding articles to be cleaned, a tinnedwire glrid within said container and soldered to t e bottom thereof, and means for lowering said container and itscontents first into said electrolyte and then immediately into said heated water.

5. Apparatus for cleaning tarnished metal articles by electrolytic action, said apparatus comprising a perforate zinc container having a tinned wire grid soldered thereto, and means for continuously heating said container and its contents.

6. The combination of a perforate zinc container, 9. tinned wire grid soldered therein for supporting metal articles to be cleaned, a receptacle for holding an alkaline electrolyte, and mechanism for lowerin" said container into said receptacle to effect the cleaning of said articles and for withdrawing the container therefrom to drain off the electrolyte.

7. In a cleaning apparatus, a receptacle for holding an alkalme electrolyte, means for continuously heating said electrolyte, a perforate zinc container having a tinned wire grid soldered therein to support metal articles to be cleaned, and means for lowering said zinc container into said electrolyte and for withdrawing it therefrom.

8. In an apparatus for cleaning metal articles, the combination of a receptacle for holding an alkaline electrolyte, means for maintaining said electrolyte continuously heated, a second receptacle for holding heated water, a perforate zinc container having a tinned wire support for articles to be cleaned, and means for lowerin said holding a heated alkaline electrolyte, a zinc container for holding articles to be cleaned,

said containerhaving a flat perforate bottom, a tinned wire grid soldered to said perforate bottom and adapted to make electrical connection with the articles to be cleaned, mechanism for bringing said electrolyte into contact with said container to clean the articles carried thereby, and a washing bath for removing the last of said electrolyte while the articles to be cleaned still make contact with said wire grid.

10. In an apparatus for cleaning metal articles, the combination of a receptacle for holding an alkaline electrolyte, means for introducing steam into said electrolyte, a second receptacle for holding water, means for maintaining said water continuously heated, a zinc container for holding articles to be cleaned, said container having a fiat bottom with perforations therein,.a tinned grid Within said container and soldered thereto, said grid comprising wires welded.

- JAMES D. PHILLIPS.

CARL HAMBUECHEN.

Witnesses:

A. O. OLMAN, L. S. LUNDER. 

